Mechanically actuated fuel injectors in conventional engine assemblies typically incorporate an injector train having a rocker arm with two ends, one of which is mechanically coupled to the fuel injector and the other of which is mechanically coupled to a pushrod. The pushrod is coupled to an cam follower which engages an eccentric cam on the engine camshaft.
The rotation of the camshaft and the eccentric cam causes the cam follower, the pushrod, and the rocker arm to reciprocate. The reciprocation of the rocker arm causes the fuel injector to periodically inject fuel into the engine cylinder with which it is associated. One example of such an engine assembly is disclosed in U.S. Pat. No. 5,035,209 to Braker, et al.
In some engine assemblies of the type described above, there may be some intermittent, slight mechanical separation between the components of the injector train. For example, during each fuel injection cycle, the rocker arm may become temporarily separated from the pushrod. That temporary separation, which lasts for only a portion of the fuel injection cycle, may cause excessive noise when the pushrod again makes contact with the rocker arm later in the injection cycle. The temporary separation of the injector train components may have other disadvantages.